Power bank



FIG. 1 is a front, top perspective view of a power bank comprising an embodiment of a new, original and ornamental design;

FIG. 2 is another front, top perspective view thereof with a car battery charging port exposed;

FIG. 3 is a front view thereof;

FIG. 4 is another front view thereof with a car battery charging port exposed;

FIG. 5 is a back view thereof;

FIG. 6 is a left-hand side view thereof;

FIG. 7 is a right-hand side view thereof;

FIG. 8 is a top view thereof; and,

FIG. 9 is a bottom view thereof.

The broken line portions of the figure drawings are included to show unclaimed subject matter only and form no part of the claimed design. 

CLAIM The ornamental design for a power bank, substantially as shown and described. 